Automatic belt take-up pulley



Feb. 13, 1951 P, JER-EB 2,541,766

AUTOMATIC BELT TAKE-UP PULLEY Filed Nov. 25 1949 Paul cfer Z Patentecl Feb. 13, 1951 UNITED STATES PATENT OFFICE.-

AUTOMATIC BELT TAKE-UP PULLEY Paul J ereb, Oakland, Calif.

Application November 25, 1949, Serial No. 129,471

This invention relates to a novel construction of pulley having means for automatically tensioning a belt trained thereover and for grippin the opposite sides of the belt to minimize slippage thereby improving the life of the belt and reducing strain on the shafts connected by the belt.

Another object of the invention is to provide a novel belt pulley which permits V-belts of different widths to be utilized with the belt pulley.

, Still another and particular important object of the present. invention is to provide corresponding pulley halves or sections each of which may rotate in either direction relatively to a shaft on which the pulley is mounted and within a limited are for causing said belt pulley sections to be displaced either toward or away from one another for properly accommodating the pulley halves to belts of different widths and for automatically taking up slack in a belt.

Still another object of the invention is to provide means for causing the two pulley halves to rotate relatively to their supporting shaft in unison.

Various other objects and advantages of the invention ill'hereinafter become more fully apparent from the following description of the drawing, illustrating preferred embodiments thereof, and wherein:

Figure 1 is a top plan view showing one embodiment of the invention and with the pulley halves thereof displaced away from one another;

- Figure 2is a sectional view taken substantially along a plane as indicated by the line 2-2 of Figure 1;

'. Figure 3 is an exploded side elevational view showing one pulley half and its associated cam member;

s Figure 4 is a View similar to Figure l illustrating another embodiment of. the invention, and

Figure 5 is a cross sectional view taken substantially along a plane as indicated by the line 5-5 of Figure 4.

Referring more specifically to the drawing and first with reference to the form of the invention as illustrated in Figures 1, 2 and 3, the automaticallyadjustable belt pulley as disclosed therein is designated generally I and includes a belt pulley mounting which is illustrated as a sleeve 8 which is provided with longitudinally spaced longitudinally algned threaded openings 9 for receiving screwsIU. The sleeve 8 is adapted to be mounted on either a motor or other drive shaft or on a driven shaft and the screws Ill may be advanced into the bore thereof for se- 7 Claims. (Cl. 74-23024) curing the sleeve 8 to said shaft, not shown, for causing said sleeve to be revolved with the shaft. However, if desired, the belt pulley, hereinafter to be described, may be mounted directly on a drive shaft or driven shaft and the sleeve 8 may be assumed to represent a portion of said shaft.

The belt pulley, designated generally H in cludes corresponding pulley halves or sections, each designated generally I2 and which are adapted to engage a belt of V-shaped cross section, as illustrated in cross section at It in Figures 1 and 2. The pulley halves I2 are provided with corresponding. outwardly diverging sides M which are adapted to receive therebetween the opposite, outwardly diverging sides of the V-belt I3. The pulley sections I2 each include an inner hub portion I5 which hub portions extend from the inner portions of the faces I4 toward one another. The pulley halves I2 are likewise each provided with an outwardly projecting hub portion I6 and said hub portions I 6 are provided with corresponding outer ends or faces H which are disposed diagonally to the longitudinal axis or plane of the pulley halves; I2 and to the axis of the sleeve 8.

The pulley halves I2 are provided with cor-,- responding bores or recesses I8 which extendparallel to the axis of the sleeve 8 and which are disposed in corresponding relationship to the outer hub portions I6. A pin I9 has its end slidably disposed in the recesses I8 for connecting the pulley halves I2 to cause said pulley halves to turn in unison but whichpermit said pulley halves to slide toward or away from one another on thesleeve 8.

The pulley halves I2 are retainedon the sleeve 8 between a pair of retaining collars 23 each having an opening 2| through which one of the screws I0 extends, so that the collars 28 are? secured to the sleeve 8 by said screws Ii]. .The collars 20 additionally function as cam members and have corresponding inner faces 22 which are disposed at the same angle as the hub ends orfaces I! and which are adapted to be engaged by said hub faces. When the pulley halves I2 are disposed as seen in Figures 1 and 2 and with the faces I! and 22 in flush abutting engage-c ment, said pulley halves will be spaced a maxi-v mum distance from one another. Accordingly, when the pulley II is revolved either by the sleeve 8 being turned or by being driven by the belt I3;

if the sleeve 8 is revolved or driven it will initially turn relatively to the pulley II, due to the drag on the pulley caused by the belt I3, and as this occurs the collars 20 will be turned relativelyto the outer hub portions IE to cause the widest part of each collar to move toward tlte widest part of the adjacent hub portion is to thereby through a camming action displace the pulley halves l2 uniformly toward one another for gripping the belt between the pulley faces M to cause said belt to be driven and if any slack exists in the belt for displacing the belt radially toward the periphery of the pulley H to thereby tension the belt. It will be readily apparent that this will occur irrespective of which direction the sleeve 8 and collars 20 are revolved relatively to the pulley II for thus automatically tensioning the belt I3 and for causing the pulley to properly grip the belt to prevent or at least minimize slippage between the belt and pulley and therefore reduce wear. Likewise, if the belt is is driven it will initially cause the pulley H to turn relatively to the sleeve 8 and collars 20 for similarly displacing the pulley halves toward one another, due to the drag or resistance to rotation offered by the sleeve 8 and the shaft to which it is connected. Obviously, the spacing between the collars 20 may be varied by adjusting the distance between the openings 9 or by providing additional openings 9 for varying the space between the pulley halves [2 to thereby accommodate the pulley II to belts of different widths.

Figures 4 and 5 illustrate another embodiment of the automatic belt tensioning pulley, designated generally la and which likewise includes a pulley mounting means which may be formed by a sleeve 8a, which is adapted to be mounted and secured to a driving or driven shaft or which may constitute a part of said shaft. As disclosed, the sleeve 8a is provided with longitudinally spaced longitudinally aligned threaded openings 9a each of which is adapted to receive the threaded shank of a headed stud [a, the heads of which studs project from the periphery of the sleeve 8a. The automatic adjusting pulley Ha includes corresponding pulley halves 12a having corresponding belt engaging faces Ma, corresponding to the faces 14 of the pulley I i. The pulley faces Ma similarly engage opposite sides of a V-belt 13a, corresponding to the V-belt 13. In lieu of the inner hub portions IS, the pulley halves 12a are provided with correspondingly circumferentially spaced hub portions [a which extend inwardly thereof. The hub portions of the two pulley sections I2a are 'stag-geredly arranged so that the hub portions or teeth l5a of each section l2a will fit into the recesses 18a of the other section 12a to provide a sliding interfitting engagement between the teeth [5a of the two pulley sections I2a to cause said pulley halves to turn in unison relatively to the sleeve 8a while permitting the pulley sections to slide forward and away from one another.

The pulley halves [2a are provided with corresponding outwardly extending external hub portions lBa the outer ends of which include spiral portions [1a which are similarly disposed and which recede toward the inner ends of the pulley halves I211. The hub portions 5a are provided with shoulders 20a which extend longitudinally of the sleeve 8a and outwardly from the inner ends of the inwardly receding spiral portions 110,. The heads of the studs a normally abut the shoulders a and the adjacent portions of the spiral edges Ha. Accordingly, if the sleeve 18a is revolved counterclockwise as seen in Figure 5 it may initially turn relatively to the pulley 'I la and in so doing the heads of the studs Hla will ride along the spiral surfaces vIla which thus form cam surfaces for causing the pulley halves l2a to be displaced toward one another as the sleeve 8a thus revolves relatively to the pulley or if the pulley is turned relatively to the sleeve 8a by the belt I30, and in a clockwise direction as seen in Figure 5, the pulley halves l2a will be similarly displaced toward one another for gripping engagement with the belt l3a and to displace said belt l3a radially outwardly of the pulley for ten'sioning the belt. However, the automatically adjustable belt pulley Illa will not function if the sleeve 8a is driven in a clockwise direction as seen in Figure 5 or if the pulley Ila is driven by the belt in a counterclockwise direction as seen in Figure 5.

Various modifications and changes are contemplated and may obviously be resorted to, without departing from the spirit or scope of the invention as hereinafter defined by the appended claims.

I claim as my invention.

1. An automatically adjustable belt pulley comprising a pulley mounting member, a belt pulley formed of corresponding pulley halves rotatably mounted on said mounting member, each of said pulley halves "having an inclined belt pulley engaging face, said beltpulley engaging faces being disposed in outwardly diverging relationship in a direction radially of the belt pulley, each of said pulley halves having an external outwardly extending hub portion provided with a cam surface at its outer end disposed at an angle to the plane of the belt pulley, and 'a' pair of stop members secured to the pulley mounting member and between which the belt pulley is disposed, said s'top members being en'- gaged by the cam surfaces for causing the pulley halves to be displaced toward one another when the mounting member is turned relatively to the belt pulley or the belt pulley is revolved relatively to the mounting member.

2. An automatically adjustable belt pulley as in claim 1, and means slidably connected to each of said pulley halves for causing the pulley'halves to revolve in unison.

3. An automatically adjustable belt pulley as in claim 1, said pulley halves having correspondingly disposed inwardly opening recesses, and a pin having its ends slidably engaging each of said recesses.

'4. An automatically adjustable belt pulley as in claim 1, said stop members each comprising a collar secured to the mounting member and having an inner side taperedffroin'one portion of the; periphery thereof to its diametrical opposite peripheral portion, said "tapered inner sides ":of the collars engaging said ca'm surfaces.

5. An automatically adjustable belt pulley "as.

convolution and forming a apart or the *outerend:

of each exterior hub portion, each of said *hub portions having a shoulder disposed longitudinally of the belt pulley and -merging with the inner ends of said spiral-cam surface, and said: stop members including. headed :studs .rbetween'" which the belt pulley is disposed, the heads of said studs engaging said spiral cam surfaces for displacing the pulley halves toward one another when the mounting member is turned in one direction relatively to the pulley or said pulley is revolved in one direction relatively to the mounting member.

7. An automatically adjustable belt pulley as in claim 1, said belt pulley halves having corresponding inwardly extending circumferentially 10 spaced hub portions, the hub portions of the two pulley halves being staggeredly arranged for interfittirjg engagement for slidably connecting the pulley halves for reciprocating movement toward 'and away from one another and for rotary movement as a. unit.

' PAUL JEREB.

No references cited. 

